org.springframework.util
Class Log4jConfigurer

Convenience class that features simple methods for custom log4j configuration.

Only needed for non-default log4j initialization, for example with a custom
config location or a refresh interval. By default, log4j will simply read its
configuration from a "log4j.properties" or "log4j.xml" file in the root of
the classpath.

For web environments, the analogous Log4jWebConfigurer class can be found
in the web package, reading in its configuration from context-params in
web.xml. In a J2EE web application, log4j is usually set up
via Log4jConfigListener or Log4jConfigServlet, delegating to
Log4jWebConfigurer underneath.

Log4jConfigurer

initLogging

Initialize log4j from the given file location, with no config file refreshing.
Assumes an XML file in case of a ".xml" file extension, and a properties file
otherwise.

Parameters:

location - the location of the config file: either a "classpath:" location
(e.g. "classpath:myLog4j.properties"), an absolute file URL
(e.g. "file:C:/log4j.properties), or a plain absolute path in the file system
(e.g. "C:/log4j.properties")

initLogging

Initialize log4j from the given location, with the given refresh interval
for the config file. Assumes an XML file in case of a ".xml" file extension,
and a properties file otherwise.

Log4j's watchdog thread will asynchronously check whether the timestamp
of the config file has changed, using the given interval between checks.
A refresh interval of 1000 milliseconds (one second), which allows to
do on-demand log level changes with immediate effect, is not unfeasible.

WARNING: Log4j's watchdog thread does not terminate until VM shutdown;
in particular, it does not terminate on LogManager shutdown. Therefore, it is
recommended to not use config file refreshing in a production J2EE
environment; the watchdog thread would not stop on application shutdown there.

Parameters:

location - the location of the config file: either a "classpath:" location
(e.g. "classpath:myLog4j.properties"), an absolute file URL
(e.g. "file:C:/log4j.properties), or a plain absolute path in the file system
(e.g. "C:/log4j.properties")